Comment 1 for bug 1851521

This issue causes a lockup when I try to test MicroStack using a MicroStack cloud. Because both the top level host and the MicroStack guests are attempting to use the same network, I lose connectivity to the guests. We need to avoid binding br-ex to the network until we've given an operator a chance to fix the network (or do some intelligent discovery and avoid clobbering an existing network on the host.)